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1.
Am J Orthod Dentofacial Orthop ; 159(1): 30-40, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33127204

RESUMEN

INTRODUCTION: We evaluated soft-tissue thickness changes after bimaxillary surgery according to vertical facial patterns in patients with skeletal Class III malocclusion with mandibular prognathism. METHODS: Forty-three Korean patients (16 men and 27 women; mean age, 22.6 ± 4.1 years) with skeletal Class III malocclusion who underwent bimaxillary surgery were divided into 2 groups: normal-angle group (N group) and high-angle group (H group), on the basis of the presurgical angle of the mandibular plane relative to the sella-nasion plane (SN-MP). Changes in hard-tissue landmarks and soft-tissue thickness before and after surgery were analyzed from reconstructed 3-dimensional cone-beam computed tomography images. Postoperative soft-tissue thickness in both groups was compared with that in 40 patients with normal skeletal Class I malocclusion in the reference group. RESULTS: Group N (27°-37°) and group H (>37°) did not differ significantly in terms of sex and age before surgery. Preoperative pogonion (Pog) thickness was significantly less in group H (9.7 ± 1.6 mm) than in group N (10.8 ± 1.9 mm) (P = 0.042). Adjusted multiple linear regression analysis showed a weak positive linear relationship between the SN-MP before surgery and soft-tissue Pog thickness change (R2 of 0.361; P = 0.001) after surgery, but the area below the lower lips was not completely normalized despite surgery. CONCLUSIONS: The thickness of the soft-tissue Pog may increase slightly after surgery in patients with skeletal Class III malocclusion with a higher preoperative mandibular plane angle, but normalization in the area cannot be completely achieved despite surgery.


Asunto(s)
Maloclusión de Angle Clase III , Mandíbula , Adolescente , Adulto , Cefalometría , Cara/diagnóstico por imagen , Femenino , Humanos , Masculino , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/cirugía , Mandíbula/diagnóstico por imagen , Mandíbula/cirugía , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Adulto Joven
2.
J Prosthet Dent ; 125(1): 41-45, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32033790

RESUMEN

A facebow transfer is typically used for mounting a maxillary gypsum cast in an ideal location in a mechanical articulator. However, the facebow transfer procedure is difficult and may cause the patient discomfort. This proposed technique uses a patient's cone beam computed tomography (CBCT) data to reproduce the occlusal plane in relation to digital articulator scan data, align the patient's gypsum cast or intraoral scan data on the reproduced plane, and then transfer the data to a mechanical articulator.


Asunto(s)
Articuladores Dentales , Modelos Dentales , Oclusión Dental , Humanos , Registro de la Relación Maxilomandibular , Maxilar/diagnóstico por imagen
3.
J Prosthet Dent ; 125(1): 89-94, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32059858

RESUMEN

STATEMENT OF PROBLEM: The software programs of digital intraoral scanners typically offers the option to cut out areas from 3D casts, to do rescans, and to merge them with the initial scan. However, evidence of whether this procedure has an impact on the accuracy of the scan is lacking. PURPOSE: The purpose of this study was to determine whether "cut out-rescan" procedures change the accuracy of a 3D cast. MATERIAL AND METHODS: A maxillary master cast was digitized with an industrial structured light scanner to obtain a digital reference cast. This master cast was repeatedly scanned by 3 intraoral scanners: TRIOS 3 [TR], Cerec Primescan [PR], and Cerec Omnicam [OM]. The scan data were duplicated, and the posterior area from the right lateral incisor was cut out and rescanned to obtain complete-arch casts containing the rescanned data [TR_rs], [PR_rs], and [OM_rs]. The trueness and precision of the scans were evaluated by superimposing procedures of the relevant data sets. To evaluate statistical differences, either the Mann-Whitney U test or the t test was used (α=.05). RESULTS: The median precision values of the complete-arch scan data was 19 µm for [OM] and [TR], whereas the median for [PR] was 14 µm. In the "cut out-rescanned" data group, the values were 25 µm for [OM_rs], 16 µm for [TR_rs], and 14 µm for [PR_rs]. Statistically significant differences were found among the scanners [OM]/[PR], [OM_rs]/[TR_rs], and [TR_rs]/[PR_rs]. The mean ± standard deviation values of trueness for the complete-arch scan data were 54 ±4 µm for [OM], 42 ±5 µm for [TR], and 30 ±2 µm for [PR]. In the group of the "cut out-rescanned" data, the mean trueness results were 55 ± 6 µm for [OM_rs], 38 ±5 µm for [TR_rs], and 31 ±5 µm for [PR_rs]. Significant differences were found among the complete-arch scan data and the "cut out-rescanned" data of the different scanners, but not between the complete-arch scan data and the "cut out-rescanned" data within one scanning system. CONCLUSIONS: Significant differences were found among the scanners, but "cut out-rescan" procedures did not affect the accuracy within each scanning system.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Arco Dental , Imagenología Tridimensional , Maxilar/diagnóstico por imagen
4.
J Endod ; 47(1): 39-43, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33045268

RESUMEN

INTRODUCTION: The aim of this cone-beam computed tomographic study was to evaluate the association between the mesiobuccal root canal configuration (RCC), interorifice distance (IOD), and the corresponding root length of a permanent maxillary first molar tooth. METHODS: One hundred cone-beam computed tomographic scans obtained from the computerized data bank of the institute were studied. The IOD between the first mesiobuccal and second mesiobuccal canal was measured in the axial section where the second mesiobuccal canal was first visualized. The root length was measured from the cementoenamel junction to the root apex in the coronal and sagittal section. The associations of these parameters with the RCC (based on Vertucci's classification) were evaluated. RESULTS: The predominant RCC was observed to be Vertucci type II (89%). The mean root length with this configuration was 11.19 ± 1.35 mm. In type IV RCC, the mean root length was 9.13 ± 0.52 mm. A statistically significant association was established between the root length and RCC (P < .05). In roots with type II and type IV RCC, the mean IOD was 2.58 ± 0.04 mm and 2.62 ± 0.1 mm, respectively. No statistically significant relation was established between the IOD and the type of RCC (P > .05). CONCLUSIONS: The length of the mesiobuccal root is an important anatomic parameter for predicting the type of RCC in the permanent maxillary first molar tooth.


Asunto(s)
Cavidad Pulpar , Maxilar , Tomografía Computarizada de Haz Cónico , Cavidad Pulpar/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen
5.
J Endod ; 47(1): 19-27, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33091453

RESUMEN

INTRODUCTION: Targeted Endodontic Microsurgery (TEMS) combines trephine burs and 3D-printed guides to make flapless maxillary palatal root-end surgery possible. This study assessed the location of the greater palatine artery (GPA), the relationship of the GPA to maxillary molar root ends, and the feasibility of flapless palatal-approach TEMS. METHODS: Three endodontists analyzed 250 cone-beam computed tomographic images of maxillary molars for (1) transition morphology between the hard palate and the alveolar process adjacent to first and second molars as an indication of the most likely location of the GPA, (2) the superior-inferior relationship between the GPA and root ends, and (3) the feasibility of palatal-approach TEMS. RESULTS: Palatal transition morphology included 20% Spine, 72% Bridge, and 8% Smooth. GPA position as related to palatal root ends was classified as 34% superior, 40% adjacent, and 21% inferior. Five percent of classifications were undefined. TEMS was deemed feasible for 47% of maxillary first molars and 52% of second molars, and was significantly more feasible with GPAs superior to palatal root ends. Reasons for infeasibility included GPA proximity and unfavorable resection angle or level. Maxillary first molar palatal roots were 11.13 ± 2.68 mm from the greater palatine foramen (GPF) and 2.37 ± 1.46 mm from the GPA. Second molar palatal roots were 4.94 ± 2.55 mm from the GPF and 2.53 ± 1.77 mm from the GPA. CONCLUSIONS: Palatal transition morphology and GPA position adjacent to maxillary molars, as manifested in cone-beam computed tomographic coronal views, suggested maxillary palatal root TEMS could be accomplished with a 2-mm safety margin in 47% of first molars and 52% of second molars. Historical paradigms that do not consider flapless palatal surgical approaches may need to be revised.


Asunto(s)
Microcirugia , Raíz del Diente , Arterias , Tomografía Computarizada de Haz Cónico , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Diente Molar/diagnóstico por imagen , Diente Molar/cirugía , Raíz del Diente/diagnóstico por imagen , Raíz del Diente/cirugía
6.
J Craniomaxillofac Surg ; 48(12): 1119-1125, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33288374

RESUMEN

PURPOSE: To evaluate the surgical accuracy of a new Maxillary Bone-Dental-Supported guide (MBDS) for osteotomy and maxillary positioning in orthognathic surgeries. MATERIALS AND METHODS: The customized MBDS were prototyped through CAD-CAM technology (computer-aided design and manufacturing). The planning image (CT0) was superimposed on the computed tomography scan post-treatment (CT1) and the mean of positional differences between them were obtained tridimensionally at the axes: mediolateral (X), anteroposterior (Y) and vertical (Z). RESULTS: Eleven patients were selected according to the inclusion and exclusion criteria. The mediolateral movement showed the best precision, with a greater mean difference of 0.34 mm at the CI point (central incisor) and less than 0.02 mm at the RM point (right molar). In the vertical direction, the largest mean discrepancy found was 0.50 mm and on the y-axis, anteroposterior, was 0.74 mm, as well as two at the CI point. The skeletal SNA point, on the other hand, showed the smallest average discrepancies: 0.10 mm (x-axis), 0.03 mm (y-axis) and 0 mm (z-axis). Overall, 99.24% of the discrepancies found were less than 2 mm. CONCLUSION: Our results suggests that the double support, osseous and dental, present in that new guide, favored the positional stability of the maxilla and promoted better control of its vertical axis. Furthermore, the function of an osteotomy guide increases the predictability and security of the surgical procedure.


Asunto(s)
Cirugía Ortognática , Procedimientos Quirúrgicos Ortognáticos , Cirugía Asistida por Computador , Diseño Asistido por Computadora , Humanos , Imagenología Tridimensional , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Tomografía Computarizada por Rayos X
7.
J Prosthet Dent ; 124(6): 761.e1-761.e7, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33289647

RESUMEN

STATEMENT OF PROBLEM: Intraoral scanners are promising options for removable prosthodontics. However, analog aids, including occlusion rims, are still used, as a completely digital workflow is challenging and scientific evidence on the topic is scarce. PURPOSE: The purpose of this in vitro study was to assess and compare the trueness and precision of scans obtained from a reference typodont of a completely edentulous maxilla by using an intraoral scanner (TRIOS 3 Pod; 3Shape A/S) with scans obtained by using a laboratory scanner (DScan 3; EGS S.R.L.) from both Type IV stone casts and polysulfide impressions. MATERIAL AND METHODS: The polyurethane resin reference typodont was replicated from a clinical cast and was scanned with a metrological machine to obtain a reference scan. Ten digital casts were obtained by applying standardized scanning strategies to the reference typodont with the intraoral scanner. A device was created to make 10 consistent polysulfide impressions, and a scan of each impression was made with the laboratory scanner and then digitally reversed to obtain 10 digital reversed casts. Ten Type IV stone casts were poured and then scanned with the laboratory scanner to obtain 10 digital extraoral scanner casts. The scans in standard tessellation language (STL) format were imported into a dedicated software program, and the trueness and precision were calculated in µm. In addition to descriptive statistics (confidence interval 95%), 1-way ANOVA followed by the Bonferroni test or the Kruskal-Wallis and the Dunn tests were used to analyze differences among groups (α=.05). RESULTS: The trueness values (95% confidence interval) were digital intraoral scanner cast=48.7 (37.8-59.5), digital reversed cast=249.9 (121.3-378.5), and digital extraoral scanner cast=308.8 (186.6-430.9); significant differences were detected between digital intraoral scanner cast and digital reversed cast (P<.001) and between digital IOS casts and digital extraoral scanner cast (P<.001). The precision values (95% confidence interval) were digital intraoral scanner cast=46.7 (29.7-63.7), digital reversed cast=271.2 (94.6-447.8), and digital extraoral scanner cast=341.4 (175.5-507.3); significant differences were detected between digital intraoral scanner cast and digital reversed cast (P=.003) and between digital intraoral scanner cast and digital extraoral scanner cast (P=.001). CONCLUSIONS: Directly scanning a solid typodont of a completely edentulous maxilla with the intraoral scanner produced better trueness and precision than scanning the polysulfide impressions or the stone casts with a laboratory scanner.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Imagenología Tridimensional , Laboratorios , Maxilar/diagnóstico por imagen
8.
J Prosthet Dent ; 124(6): 762.e1-762.e8, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33289648

RESUMEN

STATEMENT OF PROBLEM: Information about the accuracy of intraoral scanners for the edentulous maxilla is lacking. PURPOSE: The purpose of this in vitro study was to compare the accuracy of 3 different intraoral scanner techniques on a completely edentulous maxilla typodont. MATERIAL AND METHODS: Two completely edentulous maxillary typodonts with (wrinkled typodont) and without (smooth typodont) palatal rugae were used as reference and were scanned by using an industrial metrological machine to obtain 2 digital reference scans in standard tessellation language (STL) format (dWT and dST). Three different scanning techniques were investigated: in the buccopalatal technique, the buccal vestibule was scanned with a longitudinal movement ending on the palatal vault with a posteroanterior direction; the S-shaped technique was based on an alternate palatobuccal and buccopalatal scan along the ridge; in the palatobuccal technique, the palate was scanned with a circular movement and then with a longitudinal one along the buccal vestibule. Consecutively, 6 types of scans were obtained (n=10), namely wrinkled typodont/buccopalatal technique, wrinkled typodont/S-shaped technique, wrinkled typodont/palatobuccal technique (wrinkled typodont), smooth typodont/buccopalatal technique, smooth typodont/S-shaped technique, and smooth typodont/palatobuccal technique (smooth typodont). Scans in STL format were imported into a dedicated software program, and trueness and precision were evaluated in µm. In addition to descriptive statistics (95% confidence interval), a 2-factor ANOVA on the data ranks, the Kruskal-Wallis, and the Dunn tests were performed to analyze differences among groups (α=.05). RESULTS: Mean values for trueness (95% confidence interval) were wrinkled typodont/buccopalatal technique=48.7 (37.8-59.5); wrinkled typodont/S-shaped technique=65.9 (54.9-77.4); wrinkled typodont/palatobuccal technique=109.7 (96.1-123.4); smooth typodont/buccopalatal technique=48.1 (42.4-53.7); smooth typodont/S-shaped technique=56.4 (43.9-68.9); smooth typodont/palatobuccal technique=61.1 (53.3-69), with statistically significant differences for wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P<.001), buccopalatal technique versus palatobuccal technique (P<.001), and wrinkled typodont versus smooth typodont (P=.002). Mean values for precision (95% confidence interval) were wrinkled typodont/buccopalatal technique=46.7 (29.7-63.7); wrinkled typodont/S-shaped technique=53.6 (37.6-69.7); wrinkled typodont/palatobuccal technique=90 (59.1-120.9); smooth typodont/buccopalatal technique=46 (39.7-52.3); smooth typodont/S-shaped technique=76 (55.5-96.6); smooth typodont/palatobuccal technique=52.9 (41.9-63.8); with statistically significant differences for buccopalatal technique versus palatobuccal technique (P=.032) and wrinkled typodont/buccopalatal technique versus wrinkled typodont/palatobuccal technique (P=.012). CONCLUSIONS: Smooth typodont scans showed better trueness than wrinkled typodont scans. Buccopalatal technique showed better mean values for trueness and precision than palatobuccal technique only in the wrinkled typodont scenario, while the other scanning approaches did not show significant differences in either tested configuration.


Asunto(s)
Técnica de Impresión Dental , Modelos Dentales , Diseño Asistido por Computadora , Imagenología Tridimensional , Maxilar/diagnóstico por imagen
9.
BMC Oral Health ; 20(1): 303, 2020 11 04.
Artículo en Inglés | MEDLINE | ID: mdl-33148234

RESUMEN

BACKGROUND: A large number of articles in recent years studying the effects of non-surgically assisted tooth- versus bone-borne maxillary expanders in growing patients have found no significant differences in mid-palatal suture disjunction or even dentoalveolar changes. This suggests the need for new criteria and better use of current technology to make more effective devices and enhance the benefits of conventional treatments. This article describes a titanium grade V computer-aided design/computer-aided manufacturing (CAD/CAM) maxillary expander supported by two miniscrews, along with a 3D printed surgical guide. METHODS: The first step was to obtain a digitized model of the patient's upper maxilla. To simplify the process and ensure the placement of the device in a high-quality bone area, the patients' digital dental cast was superimposed with a cone beam computed tomography (CBCT) scan. Improved resistance to expansion forces was secured through the use of 2 mm-wide miniscrews, long enough for bicortical anchorage. Placement site and direction were assessed individually in order to achieve primary stability. We chose a site between the second premolars and first molars, while the inclination followed the natural contour of the palate vault. A 3D-printed, polyamide surgical guide was designed to ensure the correct placement of the device with a manual straight driver. RESULTS: Favorable clinical results were presented with 3D images. We confirmed a mid-palatal suture parallel separation of 3.63 mm, along with a higher palatal volume, as well as increased intercanine and intermolar distance. Segmentation of the facial soft tissue showed an expansion of nasal airways and changes in nasal morphology. CONCLUSIONS: Digital models, CBCT and CAD/CAM technology, are essential to accomplish the goals proposed in this article. Further studies are necessary to establish safer miniscrew placement sites and insertion angles so as to achieve greater in-treatment stability. Both the clinician and the patient can benefit from the use of current technology, creating new devices and updating traditional orthodontic procedures.


Asunto(s)
Maxilar , Tomografía Computarizada de Haz Cónico Espiral , Diseño Asistido por Computadora , Tomografía Computarizada de Haz Cónico , Humanos , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Técnica de Expansión Palatina , Tecnología
10.
Am J Orthod Dentofacial Orthop ; 158(6): e111-e120, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33158633

RESUMEN

INTRODUCTION: This single-centered, parallel-groups trial aimed to evaluate the efficacy of traditional corticotomy vs flapless corticotomy in accelerating en-masse retraction. In addition, to assess the skeletal, dental, and soft-tissue variables, as well as the external apical root resorption (EARR) of the maxillary anterior teeth. METHODS: Forty patients with Class II Division 1 malocclusion aged >18 years at the beginning of treatment, requiring maxillary first premolar extractions, were randomly distributed into 2 groups (n = 20 each): 1 group was treated using traditional corticotomy, and the other group was treated with flapless corticotomy in en-masse retraction with anchorage based on miniscrews placed between maxillary second premolars and first molars bilaterally. Randomization was implemented with a computer-generated list of random numbers; allocation was concealed in sequentially numbered, opaque, sealed envelopes. The study was single-blinded (outcomes' assessor). The primary outcome was the en-masse retraction duration. Secondary outcomes were the skeletal, dental, and soft-tissue changes on lateral cephalometric and the EARR of maxillary anterior teeth on digital panoramic radiographs. RESULTS: The en-masse retraction duration in the flapless corticotomy group was longer than the traditional corticotomy group. The average retraction duration was 4.04 ± 1.10 months for the flapless corticotomy group and 3.75 ± 2.14 months for the traditional corticotomy group, with no significant difference between the 2 groups (95% confidence interval [CI], -0.81 to 1.39; P = 0.59). No significant differences were observed between the 2 groups regarding changes in several lateral cephalometric variables (eg, SNA angle [95% CI, -2.55° to 1.66°; P = 0.67], SN-U1 angle [95% CI, -1.70° to 1.32°; P = 0.80], and UL-E [95% CI: -1.33 to 1.00 mm; P = 0.78]) or in the amount of EARR in the maxillary anterior teeth (P = 0.31). The proportion of the observed EARR ranged from 1% to 6% of root length in both corticotomy groups. No serious harms were observed in both groups. CONCLUSIONS: No significant differences between the flapless and traditional corticotomies were found in terms of the skeletal, dental, and soft-tissue variables as well as in the amount of EARR. Corticotomy-assisted en-masse retraction led to improvements in skeletal structures and facial profile and resulted in sufficient retraction of maxillary anterior teeth, slight distal movement of maxillary first molars, and an intrusion movement for both anterior and posterior teeth. Both corticotomy techniques did not cause significant EARR. REGISTRATION: ClinicalTrials.gov (Identifier: NCT03279042). PROTOCOL: The protocol was not published before the trial commencement.


Asunto(s)
Maloclusión de Angle Clase II , Métodos de Anclaje en Ortodoncia , Adolescente , Diente Premolar/cirugía , Cefalometría , Humanos , Maloclusión de Angle Clase II/cirugía , Maxilar/diagnóstico por imagen , Maxilar/cirugía , Técnicas de Movimiento Dental
11.
Artículo en Inglés | MEDLINE | ID: mdl-33151187

RESUMEN

Pterygoid implant placement has not been a common treatment modality to manage the atrophic posterior maxilla. This randomized, controlled clinical trial evaluated the accuracy of dynamic navigation using trace registration (TR) technology in pterygoid implant placement when compared to free-hand surgery. Partially edentulous patients requiring at least one pterygoid implant to rehabilitate the atrophic posterior maxilla were included. Implant accuracy (in a prosthetically directed context) and the relation of the placed implants to the greater palatine canal (GPC) were evaluated using EvaluNav to compare the preoperative CBCT plan with the postoperative CBCT implant location. Osseointegration success, mucosal thickness, implant length, time spent for surgical placement, and ease of prosthetic restorability via degree of multi-unit abutment angulation were assessed. A total of 63 pterygoid implants were placed (31 using TR, 32 using free-hand) in 39 partially edentulous patients. Mean deviations between the planned and actual position for TR-placed implants were 0.66 mm at the coronal level, 1.13 mm at the apical level, 0.67 mm in depth, and 2.64 degrees of angular deviation, compared to 1.54 mm, 2.73 mm, 1.17 mm, and 12.49 degrees, respectively, for free-hand implants. In relation to the GPC, TR implants were more accurate when compared to the presurgical plan and took less surgical time. The mean mucosal thickness measured for all implants was 5.41 mm. Most implants were 15 to 18 mm long, and most prostheses (92%) could be accommodated by a 17- or 30-degree multi-unit screw-retained abutment. TR implants had greater short-term osseointegration success rates than free-hand implants (100% vs 93.75%). Pterygoid implant surgery can be a predictable and successful modality for prosthetically directed implant rehabilitation in the atrophic posterior maxilla, is more accurate than free-hand surgery, and takes less time when using dynamic navigation via TR.


Asunto(s)
Implantes Dentales , Boca Edéntula , Cirugía Asistida por Computador , Implantación Dental Endoósea , Humanos , Maxilar/diagnóstico por imagen , Maxilar/cirugía
12.
Artículo en Inglés | MEDLINE | ID: mdl-33151198

RESUMEN

The aim of this study was to describe the basal bone and alveolar process in the maxillary anterior region by assessing patient CBCT scans. Parasagittal reconstructions were made to quantify basal bone and alveolar process dimensions and inclination of teeth in the maxillary anterior region. The CBCT scans of 87 patients and 522 tooth sites were included in this study. The results showed that the surface areas of the basal bone, alveolar process, and palatal triangle varied from 22.1 to 54.1 mm2, 87.8 to 144.0 mm2, and 37.1 to 66.0 mm2, respectively. The basal bone in the canine region had a significantly smaller cross-sectional area than in the incisor region. The alveolar process in the canine region was markedly larger than those of the central and lateral incisor regions. The mean overall thickness of the alveolar facial bone at 3, 5, and 7 mm above the CEJ were 0.6 ± 0.5 mm, 0.9 ± 0.5 mm, and 0.7 ± 0.6 mm, respectively. Additionally, the findings demonstrated that the cross-sectional area of the alveolar process and palatal triangle were greater among men than women. The study identified significant anatomical differences among various tooth regions in the anterior maxilla. The results also demonstrated that the tooth type, but not the tooth inclination or apex location, correlates with the size of the alveolar process.


Asunto(s)
Proceso Alveolar , Tomografía Computarizada de Haz Cónico , Proceso Alveolar/diagnóstico por imagen , Femenino , Humanos , Incisivo , Masculino , Maxilar/diagnóstico por imagen , Paladar (Hueso)
13.
Artículo en Inglés | MEDLINE | ID: mdl-33151201

RESUMEN

From a sample of 108 periodontally healthy volunteers with different combinations of morphometric data related to maxillary central anterior teeth and the surrounding soft tissues, this article aims to categorize gingival phenotypes according to tooth and gingival parameters, as well as assess the relationships between tooth shape and gingival characteristics, such as the papillary height (PH) and faciolingual thickness (FLT) of the papilla base. The periodontal phenotypes of 108 volunteers were confirmed using the periodontal probe transmission method for Kan classification. The FLT, PH, and the crown width to crown length (CW/CL) ratio for maxillary anterior teeth were measured. K-clustering was used to classify the anterior tooth shape into three groups: triangular, square, and compound. The mean CW/CL ratio for the maxillary anterior tooth position of the thick phenotype was greater than that of the thin phenotype. The PH and FLT for the maxillary anterior interdental papillae were greater for the thin phenotype group than for the thick phenotype group. A negative correlation was observed between the CW/CL ratio and both PH and FLT (P < .05 for both). However, a significant positive correlation was observed between FLT and PH. CW/CL ratio, FLT, and PH were all associated with the gingival phenotype with significant statistical correlations (P < .05 for all). Triangular teeth were correlated with scallop-shaped gingiva in the faciolingual area, while square teeth were associated with a flat gingiva.


Asunto(s)
Dentición , Encía , Coronas , Humanos , Maxilar/diagnóstico por imagen , Odontometría , Corona del Diente/diagnóstico por imagen
14.
Niger J Clin Pract ; 23(11): 1487-1493, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33221770

RESUMEN

Objective: The purpose of this study was to determine the amount of bone available for harvesting from the anterior palate region using IOPA (Intra Oral Peri Apical) radiographs. Materials and Methods: A total of 80 patients visiting the outpatient Department of Periodontics were selected. Two groups of male and female consisting 40 patients each were made. They were further subdivided into two groups based on age, 18-30 and 31-60 years of age, each with twenty patients. The patients were subjected to radiographic examination consisting of IOPA radiographs. All IOPA radiographs were taken using long cone paralleling technique. Availability of bone for harvesting, above the apices of teeth was calculated. Results: The bone available in the incisor region was approximately 6.5 to 6.9 mm in height and 7.4 to 8 mm in width, in canine region 6.35 to 6.65 mm in height and 7.6 to 8.1 mm width, and in the premolar region 3.65 to 3.75 mm in height and width. When the bone height and width were compared gender and age wise for CI (central incisors), LI (lateral incisors), canine and premolars, using Student's t- test the results were not statistically significant. Conclusion: For the purpose of harvesting autogenous bone, from the region of incisor and canine approximately 6.35 to 6.9 mm height and 7.4 to 8.1 mm width of bone may be harvested maintaining a safe distance from the apices of the teeth and the nasal floor. The premolar region does appear to yield sufficient bone at safe distances from the maxillary sinus and the apices of the premolars.


Asunto(s)
Trasplante Óseo , Tomografía Computarizada de Haz Cónico/métodos , Maxilar/diagnóstico por imagen , Paladar Duro/diagnóstico por imagen , Adulto , Femenino , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Paladar Duro/cirugía , Interpretación de Imagen Radiográfica Asistida por Computador , Adulto Joven
15.
Prog Orthod ; 21(1): 42, 2020 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-33225406

RESUMEN

BACKGROUND AND OBJECTIVES: Micro-implant-assisted expanders have shown significant effects on the mid-face, including a degree of asymmetry. The aim of this study is to quantify the magnitude, parallelism, and asymmetry of this type of expansion in non-growing patients. METHODS: A retrospective study on a sample of 31 non-growing patients with an average age of 20.4 years old, with cone beam computed tomography images taken before and right after expansion using maxillary skeletal expander (MSE) were assessed for skeletal expansion at three landmarks bilaterally. RESULTS: Average magnitude of total expansion was 4.98 mm at the anterior nasal spine (ANS) and 4.77 mm at the posterior nasal spine (PNS) which showed statistical significance using a paired t test with p < 0.01. Average expansion at the PNS was 95% of that at the ANS. The sample was divided into symmetric (n = 15) and asymmetric (n = 16) based on the difference in expansion at the ANS, with 16 out of 31 patients exhibiting statistically significant asymmetry. CONCLUSIONS: MSE achieves distinctly parallel expansion in the sagittal plane but can exhibit asymmetrical expansion in the transverse plane.


Asunto(s)
Maxilar , Técnica de Expansión Palatina , Adulto , Tomografía Computarizada de Haz Cónico , Cara , Humanos , Maxilar/diagnóstico por imagen , Estudios Retrospectivos , Adulto Joven
16.
Head Face Med ; 16(1): 29, 2020 Nov 20.
Artículo en Inglés | MEDLINE | ID: mdl-33213460

RESUMEN

BACKGROUND: Periodontal health is of great concern for periodontists and orthodontists in the inter-disciplinary management of patients with bimaxillary protrusion. The aim of present study is to investigate changes in the alveolar bone in the maxillary incisor region and to explore its relationship with displacement of root apex as well as changes in the inclination of maxillary incisors during incisor retraction. METHODS: Samples in this retrospective study consisted of 38 patients with bimaxillary protrusion. Cone-beam computed tomography (CBCT) images was taken before(T0) and after (T1) treatment. Alveolar bone thickness (ABT), height (ABH) and area (ABA) were utilized to evaluate changes in the alveolar bone, while incisor inclination and apex displacement were used to assess changes in the position of maxillary central and lateral incisors. Correlations between alveolar bone remodeling and apex displacement as well as changes in the inclination were investigated. RESULTS: The labial ABT of central and lateral incisors at the mid-root third was increased. In contrast, the palatal ABT at crestal, mid-root and apical third level were consistently decreased. ABH was not altered on the labial side, while significantly decreased on the palatal side. ABA was not significantly increased on the labial side, but significantly decreased on the palatal side, leading to a significantly reduced total ABA. Orthodontic treatment significantly reduced inclination of upper incisors. Changes in the amount (T1-T0) of ABA was remarkably correlated with apex displacement and changes of inclination (T1-T0); in addition, using the multivariate linear regression analysis, changes of ABA on the palatal side (T1-T0) can be described by following equation: Changes of palatal ABA (T1-T0) = - 3.258- 0.139× changes of inclination (T1-T0) + 2.533 × apex displacement (T1-T0). CONCLUSIONS: Retraction of incisors in bimaxillary protrusion patients may compromise periodontal bone support on the palatal side. An equation that incorporated the displacement of root apex and change in the incisor inclination may enable periodontist-orthodontist interdisciplinary coordination in assessing treatment risks and developing an individualized treatment plan for adult patients with bimaxillary protrusion. Moreover, the equation in predicating area of alveolar bone may reduce the risks of placing the teeth out of the bone boundary during 3D digital setups.


Asunto(s)
Incisivo , Técnicas de Movimiento Dental , Adulto , Remodelación Ósea , Cefalometría , Tomografía Computarizada de Haz Cónico , Humanos , Incisivo/diagnóstico por imagen , Maxilar/diagnóstico por imagen , Estudios Retrospectivos
17.
Orthod Fr ; 91(3): 239-248, 2020 10 01.
Artículo en Francés | MEDLINE | ID: mdl-33146618

RESUMEN

The aim of our study was to evaluate the effect of treatment with a maxillary protraction appliance on the development of the craniofacial structures and to describe the correlation between the skeletal changes and the sagittal airway dimension associated with tongue, soft palate, and hyoid bone position in skeletal Class III children. A total of 40 patients with Class III malocclusions were evaluated by the use of lateral cephalograms. Pretreatment and posttreatment cephalometric radiographs were analyzed; linear and angular measurements were performed by the same orthodontist. The effect of treatment with a maxillary protraction appliance on the development of the craniofacial structures were evaluated by Student's T test and the correlation between treatment changes in craniofacial morphology and those in upper airway, tongue, soft palate, and hyoid position was evaluated by Pearson's correlation test. A significant increase in maxillary forward growth, inhibition of mandibular forward growth, and clockwise rotation of the mandible were observed. The statistical analysis revealed that maxillary growth had a significant positive effect on the superior upper airway sagittal dimension. The nasopharyngeal airway dimensions can be improved in the short term with maxillary protraction in skeletal Class III children.


Asunto(s)
Aparatos de Tracción Extraoral , Maloclusión de Angle Clase III , Cefalometría , Niño , Humanos , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/terapia , Mandíbula , Maxilar/diagnóstico por imagen , Faringe/diagnóstico por imagen
18.
Georgian Med News ; (306): 151-155, 2020 Sep.
Artículo en Ruso | MEDLINE | ID: mdl-33130664

RESUMEN

The aim of the research was to the study morphological features of the maxilla in people of different ages according to the results of craniometric researches. A craniometric study was performed on 50 bone preparations of the skull with the calculation of the main indices of the skull, including cranial, facial, high-longitudinal, high-latitude, transverse-zygomatic and frontal-zygomatic indices, as well as the main linear parameters of the maxilla - length, width and height. In the studied material, three main morphological types of the structure of the skull are presented: brachycrania (people with round head), mesocrania (people with middle head) and dolichocrania (people with long head). More often than others there was a brachycranial form, in which a decrease in the height-longitudinal parameters of the skull was observed, at the same time in dolichocracy there was an increase in the height-longitudinal and height-latitude parameters, in mesocracy - their intermediate indicators. The variability of the skull indices determines the variability of the main parameters of the maxilla. In people with a brachymorphic skull, a wider type of the facial section and, accordingly, of the maxilla is observed, in skulls with a meso- and dolichomorphic form of structure, on the contrary, the middle and narrow type of the maxilla is more common.


Asunto(s)
Maxilar , Cráneo , Cefalometría , Humanos , Maxilar/diagnóstico por imagen , Cráneo/diagnóstico por imagen
19.
Am J Orthod Dentofacial Orthop ; 158(5): e99-e109, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33131571

RESUMEN

INTRODUCTION: This research aimed to compare the estimation error of the root axis using 3-dimensional (3D) tooth models at the midtreatment stage between the whole-surface scan (WSS) and lingual-surface scan (LSS) methods. METHODS: The sample consisted of 208 teeth (26 each of central incisors, canines, second premolars, and first molars in the maxillary and mandibular dentition) from 13 patients whose pre- and midtreatment intraoral scan and cone-beam computed tomography (CBCT) were available. The 3D tooth models were constructed by merging the intraoral-scan crowns and the CBCT-scan roots obtained at the pretreatment stage. To estimate the root axis at the midtreatment stage, we superimposed the individual 3D tooth models onto the midtreatment intraoral scan obtained by the WSS and LSS methods. The midtreatment CBCT scan was used as the gold standard to determine the real root axis. The estimated root axis in terms of mesiodistal angulation and buccolingual inclination was measured in the WSS and LSS methods, and statistical analysis was performed. RESULTS: The estimation errors of the mesiodistal angulation and buccolingual inclination were <2.0° in both methods. The LSS method demonstrated a statistically larger but clinically insignificant estimation error than the WSS method in the mandibular canine (mesiodistal angulation, 1.95° vs 1.62°) and the total tested teeth (mesiodistal angulation, 1.40° vs 1.29°; buccolingual inclination, 1.51° vs 1.41°). CONCLUSIONS: Because the estimation errors of the root axis angle using the 3D tooth model by the WSS and LSS methods were within the clinically acceptable range, the root axis can be estimated by both methods.


Asunto(s)
Modelos Dentales , Raíz del Diente , Tomografía Computarizada de Haz Cónico , Humanos , Maxilar/diagnóstico por imagen , Corona del Diente/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen
20.
BMC Oral Health ; 20(1): 274, 2020 10 07.
Artículo en Inglés | MEDLINE | ID: mdl-33028327

RESUMEN

BACKGROUND: The aim of this study was to analyze the root and canal morphology of the maxillary permanent first molars in an Emirati population using cone-beam computed tomography (CBCT). METHODS: Two hundred and sixty-one CBCT scans were acquired. The data were extracted and anonymized to remove all patient identifiers. Two observers (an endodontic resident and an endodontist) evaluated all scans on diagnostic quality monitors. RESULTS: The prevalence of a second mesiobuccal canal (MB2) was 80.1% in all examined samples. Type II Vertucci classification, was the most common canal configuration (59%) in the mesiobuccal root, followed by Types I (19.9%) and IV (15.3%), while Type III was the least common (5.7%). Types I, II, and IV were significantly more common in the 21-40-year age group (P < 0.001), while Type III was observed significantly more often in the < 20-year age group (P < 0.001). No significant effect of gender on the prevalence of Vertucci classification in the mesiobuccal root of maxillary first molars (P = 0.74) was found. Analysis of bilateral symmetry showed that 80% teeth had perfect bilateral symmetry, whereas 20% were asymmetrical. Type II canal configuration showed the highest prevalence of bilateral symmetry (48.7%), followed by Type I (15%) and Type IV (10%), while Type III showed the least prevalence of symmetry (3%). CONCLUSIONS: This was the first study to analyze the prevalence of MB2 canal in an Emirati population. Our results indicate high prevalence of MB2 (80.1%) and emphasize the importance of using advanced techniques to locate the MB2 canal.


Asunto(s)
Tomografía Computarizada de Haz Cónico , Diente Molar , Cavidad Pulpar/diagnóstico por imagen , Humanos , Maxilar/diagnóstico por imagen , Diente Molar/diagnóstico por imagen , Raíz del Diente/diagnóstico por imagen
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